1. Field of the Invention
This application relates to a disk drive and more particularly relates to the construction of the components that enclose the disks within the disk drive.
2. Description of the Related Art
One type of data storage device used in a computer to permanently store data is a disk drive. A disk drive includes at least one disk with a magnetic medium that is mounted on and rotated by a spindle motor. The disk drive also includes a data transfer head that writes data onto the magnetic medium and that reads data from the medium in concentric, generally circular tracks. In most applications, the data transfer head is extended out over the magnetic medium by an actuator assembly that moves the head in an arcuate path with respect to the medium. The tracks on the disk are divided into sectors, which are presented to the data transfer head by the rotation of the disk. An enclosure surrounds these components of the disk drive.
The servo-system includes servo data written onto the tracks that can be read by the data transfer head to give an indication of how close the head is to the centerline of a track. When the head is over the centerline of the track and follows it, the head is said to be track-following. When the head wanders from the centerline of the track, there is said to be track misregistration, or “TMR.”
Several factors influence the TMR that the disk drive will experience. For example, rotation of the disk causes airflow in the disk drive enclosure. This airflow impinges upon the disk drive components and causes vibrations in those components. For example, under certain circumstances, airflow within the enclosure causes the disks to vibrate. These vibrations cause relative motion between the tracks on the disks and the head, which increases TMR. Increased TMR is not desirable because increased TMR limits track-to-track spacing (i.e., track pitch) and consequently limits areal density.